The invention relates to a treatment device for a continuously moving web. The device has a machine frame and a container that is supported in the machine frame to hold a treatment fluid and has a drum that can rotate in the container in the treatment fluid. This drum has a cylindrical, fluid-permeable circumference, at the bottom of which the web rests against the region which is immersed in the container, at a looping angle of at least, and further has a driven eccentric shaft which is rotationally mounted in fixed external bearings. Also provided is a drum shaft that carries the drum, eccentrically mounted on the eccentric shaft, structured as a hollow shaft, and surrounding the eccentric shaft, which is rotationally mounted at its ends on regions of the eccentric shaft that are eccentric to the axis of rotation of the eccentric shaft.
Such a treatment device is described in German Patent 11 13 201. The rotating eccentric shaft has regions eccentric to its axis of rotation, on which the drum shaft is mounted by means of roller bearings. As the eccentric shaft rotates, the drum shaft and therefore the drum supported on it perform an eccentric movement. At the same time, the drum rotates, in which connection it can be entrained by the web, but also can itself be driven. The web surrounds the drum and is moved back and forth in the treatment fluid contained in the container, as the drum performs its eccentric movement, perpendicular to the plane of the fluid, thereby resulting in an increased bath exchange and an improved treatment effect, particularly washing effect.
Because of the eccentric movement of the drum, strong vibrations occur, which made a special foundation necessary for the known device. In addition, the parts of the device were subject to significant alternating stresses over an extended period of time, which placed special demands on the material.